Writing accurately can get tricky when it comes to words like “appendices or appendixes.” Are both correct? When should you use each?
If you’ve ever paused mid-sentence wondering which plural form of “appendix” is right, this guide is your ultimate reference.
We’ll break down meanings, contexts, historical roots, and style preferences, so you’ll never hesitate again.
Quick Overview
Many writers stumble over “appendices or appendixes” because the word appears in both textual and anatomical contexts. While both plural forms are technically correct, their usage depends on context and formality.
- Appendices: Preferred in formal, academic, or textual writing.
- Appendixes: Used in informal or general writing, sometimes anatomy.
By the end of this guide, you’ll understand the subtle nuances, know when to use each plural form, and confidently apply them in both professional and casual writing.
Understanding “Appendix”
The word appendix serves as a fascinating example of English borrowing and evolution. It has two primary contexts:
Textual Appendix
In books, reports, and academic papers, an appendix is supplementary material added at the end of a document. It often includes:
- Charts, graphs, or tables
- Detailed explanations or calculations
- References or citations not included in the main text
Example:
“For more details on the survey methodology, refer to the appendix at the end of the report.”
Anatomical Appendix
In anatomy, the appendix refers to a small, tube-shaped organ attached to the large intestine. While its exact function in humans is debated, it has been studied extensively in medical literature.
Fun Fact: The human appendix is typically 3–4 inches long, and while once thought useless, recent studies suggest it may play a role in gut immunity.
The Singular Form
Understanding the singular form is straightforward. Appendix refers to a single instance, whether textual or anatomical.
- Textual Example:
“The appendix includes references to all the previous studies.” - Anatomical Example:
“The doctor examined the patient’s appendix before surgery.”
Always remember: singular = one appendix, plural requires careful consideration.
Pluralization Explained
English allows flexibility, and this is where confusion arises. The plural of appendix depends on whether you are following classical Latin or modern English usage.
Classical (Latin) Plural: Appendices
Appendices comes from Latin and is traditionally used in formal writing. This is the preferred plural in:
- Academic journals
- Research papers
- Technical reports
- Anatomy textbooks
Example:
“The study includes multiple appendices detailing the experimental results.”
Modern English Plural: Appendixes
Appendixes is an English adaptation and is more common in casual writing or general publications. It is accepted in many dictionaries and often appears in:
- Newspapers
- Magazines
- Informal documents
Example:
“Check the appendixes at the end of the user manual for troubleshooting tips.”
Quick Comparison Table
| Plural Form | Usage Context | Formality Level | Notes |
|---|---|---|---|
| Appendices | Academic, textual, anatomy | High | Classical Latin plural, widely preferred in scholarly writing |
| Appendixes | Informal, general English | Medium | Acceptable in casual writing, common in US publications |
Contextual Guidelines: When to Use Each
Knowing when to use “appendices” or “appendixes” ensures your writing is professional and precise.
Use Appendices When:
- Writing academic or research papers
- Preparing technical manuals
- Referring to formal documents or books
- Using Latin-rooted traditional terminology
Use Appendixes When:
- Writing casual documents
- Publishing articles for general audiences
- Using modern, simplified English for readability
Tip: In anatomy, both are acceptable, but appendices is usually preferred in textbooks and medical journals.
Singular vs Plural Confusion in Anatomy
Anatomical usage can trip up even experienced writers.
- Singular: Appendix
- Plural: Appendices (formal) or Appendixes (informal)
Example:
- Formal: “Multiple appendices were removed during the study of digestive systems.”
- Informal: “The surgeon checked both appendixes before the operation.”
Even medical professionals sometimes choose appendices for consistency with Latin terminology.
Etymology and Historical Usage
Understanding why both forms exist requires looking at history.
- Origin: Latin appendere (“to hang”)
- Early English adoption: 14th–15th centuries
- Textual usage: Books and manuscripts borrowed the Latin plural, giving us appendices
- Modern adaptation: English writers simplified the plural to appendixes
Timeline of Usage:
| Period | Usage | Notes |
|---|---|---|
| 14th Century | Appendix in manuscripts | Singular form introduced |
| 16th Century | Appendices appears in texts | Classical plural becomes standard |
| 19th Century | Appendixes enters English | Informal plural usage grows |
| 20th Century | Both forms widely accepted | Style guides clarify formal vs informal usage |
Quote from Linguist John Algeo:
“English writers often adapt Latin plurals for readability, hence the rise of appendixes.”
Examples in Context
To help you master appendices or appendixes, here’s a practical breakdown:
Textual Usage
- Singular: “The appendix contains detailed formulas.”
- Plural (formal): “Refer to the appendices for supporting graphs.”
- Plural (informal): “The appendixes at the end of the guide help beginners.”
Anatomical Usage
- Singular: “The appendix was inflamed.”
- Plural (formal): “Some primates have multiple appendices.”
- Plural (informal): “During surgery, both appendixes were removed.”
Case Study: In a 2022 medical journal analyzing digestive systems, authors consistently used appendices when referring to multiple organ structures, reflecting the classical, academic preference.
Academic & Style Guide Preferences
Different style guides give slightly different advice:
- APA: Prefer appendices for academic papers.
- Chicago Manual of Style: Both accepted, but appendices is formal.
- MLA: Recommends appendices in scholarly work.
Regional Note:
- In UK English, appendices is almost always used.
- In US English, appendixes is acceptable in informal writing, though appendices is common in academia.
Common Questions (FAQs)
Is one form more correct than the other?
Both are correct. Use appendices for formal writing and appendixes for informal contexts.
Are there regional preferences between “appendices or appendixes”?
Yes. UK English favors appendices, while US English accepts appendixes in casual writing.
Do academic style guides prefer one form?
Yes. Most recommend appendices, especially in research and scholarly publications.
Can “appendices” and “appendixes” be interchanged safely?
Yes, in informal writing. In formal documents, stick to appendices.
How should I decide which plural to use in anatomy?
For textbooks, journals, and professional papers, use appendices. In general conversation or patient education, appendixes is fine.
Key Takeaways
- Singular: Appendix (one)
- Plural (formal): Appendices (academic, textual, anatomical)
- Plural (informal): Appendixes (general English, casual writing)
Quick Reference Table:
| Context | Singular | Plural (Formal) | Plural (Informal) |
|---|---|---|---|
| Textual | Appendix | Appendices | Appendixes |
| Anatomical | Appendix | Appendices | Appendixes |
Remember: clarity and consistency matter more than strict adherence. Choose the plural form that matches your audience and context.
